An organic light emitting diode (OLED) is a device emitting light by decaying excitons formed by holes and electrons injected into a light-emitting layer through an electrode. Such an OLED has a smaller thickness, lower power consumption, a wider viewing angle and a higher response speed than a conventional liquid crystal display since the OLED has self-emission characteristics. In addition, the OLED can be driven at a lower voltage of 10 V or less and has lower power consumption and better expression of color than a plasma display panel or an inorganic electroluminescence (EL) panel display. Moreover, the OLED may be manufactured using a flexible plastic substrate.
For compatibility of the OLED, the main problems to be solved are durability and electric conductivity. An organic material and a metal electrode included in the OLED may be easily oxidized by water. Accordingly, it is necessary to effectively prevent penetration of oxygen or water into the OLED from outside. In addition, the OLED is very vulnerable to physical impact and degradation in durability due to deterioration of the diode when heat exhaustion is not facilitated.
In the case of a current lighting device using an OLED, an encapsulating technique using an epoxy resin is applied. However, since a large amount of heat is generated while the light is constantly driven, the diode deteriorates due to the generated heat and thus fails while running.